The consequences

It took three days to evacuate the people living in the area surrounding the power station; 161,000 people had to abandon their homes. Food was immediately screened for radiation, uncontaminated food had to be imported, and agricultural production methods were rapidly modified.

At the time of the accident, 273,000 people were living in the immediate vicinity of the power plant. Some towns in the area, such as Zaborye in the Russian district of Bryansk, displayed caesium-137 contamination levels of up to 4 million Becquerel per square metre.

Immediately following the explosion and the ensuing fire fighting and rescue efforts, 203 people were admitted to hospital; 31 of these died. The UN later announced that 56 people had died from exposure to radiation caused by the explosion and related incidents.

The fatalities primarily included fire fighters and rescue workers; the people who fought to contain the blaze. It seems that neither they, nor the many other helpers, had been made aware of the acute danger of the radiation they were being exposed to. Most of these people were deployed in the area right next to the ruptured reactor without any protective gear; many were ordered to the site by the army, others were attracted by financial and other rewards. There were 210,000 so-called liquidators (approximately half of these were soldiers) plus another 400-600,000 helpers were involved later in the extensive clean-up of the accident.

The public was not informed of the radiation levels measured during the recovery work; the figures that were published were falsified. The radioactive materials released, particularly the nuclides iodine-131 and caesium-137, formed aerosols that deeply infiltrated the atmosphere. A cloud of radioactivity moved to the northwest, initially heading towards Scandinavia. The wind changed when the cloud was above the Baltic Sea, and headed southwest in a semi-circular motion, crossing the regions of Poland, Saxony, the Czech Republic and southern Germany. The wind then changed back to a north-westerly direction and blew the cloud towards the North Sea, over the Netherlands.

On its journey, the radioactive cloud moved through several areas of rain. The radioactive material was washed out of the air, and much like the fallout of a nuclear explosion, it covered and permeated the soil beneath. Many crops were directly contaminated; cows’ and goats’ milk was polluted indirectly through the food chain, as were fish and game (such as reindeer in Finland and elk in Sweden). The radioactive contamination of food, therefore, was spread far beyond northern Ukraine. The public became alarmed and intense debates over the effects of radiation contamination in food followed. In some areas, such as Bavaria, excessive traces of radiation can still be found in mushrooms today.

In heavily polluted areas, whey had to be extracted from locally produced milk and withdrawn from sale. The whey was put in storage, and entire convoys transporting the contaminated powder were shuffled from one location to the next as nobody could properly dispose of the spoilt product. The problem was discussed in the media and by the authorities for years, but no action was taken. Finally, the whey powder was incinerated – a course of action that not only cost millions but also provoked widespread protest.

Radioactive particles are easily bound and form residue very quickly. This meant that standing waters, such as reservoirs, were contaminated in the short term. At some points, local authorities even closed down communal playgrounds. Around 10,300 square km surrounding the accident site, the level of caesium-137 was in excess of 555,000 Becquerel per sq m (15 Curie per sq km).

Unnaturally high radiation was also measured in regions further a field; 7,900 sq km in Russia, 4,700 sq km in Ukraine and 16,000 sq km in Belarus displayed radiation levels exceeding 185,000 Becquerel per sq m (5 Curie per sq km). Belarus fared the worst, collecting 70% of the fallout. In many areas, up to 22% of the soil was contaminated with caesium-137. In German regions where the radioactive cloud had been passed through rain, peak caesium-137 levels of up to 100,000 Becquerel per sq m were measured.